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地铁盾构隧道重叠下穿施工对上方已建隧道的影响 被引量:139
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作者 何川 苏宗贤 曾东洋 《土木工程学报》 EI CSCD 北大核心 2008年第3期91-98,共8页
以广州地铁三号线大塘—沥滘区间盾构隧道穿越的地层条件为背景,针对盾构隧道结构的特点,引入横向和纵向不等的刚度折减系数,采用室内相似模型试验和三维有限元数值计算相结合的手段,对地铁盾构隧道重叠下穿施工所引起的上方已建隧道纵... 以广州地铁三号线大塘—沥滘区间盾构隧道穿越的地层条件为背景,针对盾构隧道结构的特点,引入横向和纵向不等的刚度折减系数,采用室内相似模型试验和三维有限元数值计算相结合的手段,对地铁盾构隧道重叠下穿施工所引起的上方已建隧道纵向变位、纵向附加轴力和弯矩、横向变形、横向附加轴力和弯矩进行了深入研究,探讨和揭示了围岩条件、隧道净距、顶推力等因素作用下盾构隧道重叠下穿施工所引起的已建隧道的变形和附加内力分布变化的影响规律。研究结果表明,新建盾构隧道施工所引起的已建隧道最大隆起点位于掌子面前方约2D(2倍直径)附近,不均匀沉降主要出现在约掌子面前方3D到后方2D的范围内,顶推施工将引起已建隧道在掌子面前方产生较大附加内力,而对后方影响较小,具体视隧道埋深、间距、围岩和施工因素而定。 展开更多
关键词 盾构隧道 重叠 等效刚度 附加内力
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Short-term outcomes of overlapped delta-shaped anastomosis, an innovative intracorporeal anastomosis technique, in totally laparoscopic colectomy for colon cancer 被引量:20
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作者 Hai-Tao Zhou Peng Wang +2 位作者 Jian-Wei Liang Hao Su Zhi-Xiang Zhou 《World Journal of Gastroenterology》 SCIE CAS 2017年第36期6726-6732,共7页
AIM To introduce an innovative intracorporeal anastomosis technique named overlapped delta-shaped anastomosis(ODA)for colon cancer cases undergoing totally laparoscopic colectomy(TLC)and to assess its feasibility and ... AIM To introduce an innovative intracorporeal anastomosis technique named overlapped delta-shaped anastomosis(ODA)for colon cancer cases undergoing totally laparoscopic colectomy(TLC)and to assess its feasibility and safety. METHODS From January 2016 to March 2017,a total of 20consecutive patients with colon cancer accepted TLC and the ODA technique at our medical center.Patient demographics,operative outcomes,perioperative complications,and pathological results were collected and analyzed. RESULTS We successfully completed TLC and the ODA procedure in all 20 cases,including 6(30%)males and 14(70%)females.In total,11(55%),2(10%),and 7(35%)cases accepted right hemicolectomy,transverse hemicolectomy,and left hemicolectomy,respectively.None of the surgeries were converted to an open operation.Mean operative time was 178.5 min,and mean estimated blood loss was 58.5 m L.Mean time to first flatus was 2.5 d,and mean postoperative hospitalization duration was 6.8 d.No severe complications occurred,such as anastomotic leakage,snastomotic stenosis,anastomotic bleeding,and wound infection,except for one case who suffered from an abdominal infection and another case who suffered from gastric paralysis syndrome.Tumor recurrence was not observed in any patient during the follow-up period. CONCLUSION The ODA technique for colon cancer cases undergoing TLC appears to be safe and feasible,although our current results need to be verified in further studies. 展开更多
关键词 overlapped delta-shaped ANASTOMOSIS Safety Totally laparoscopic COLECTOMY INTRACORPOREAL ANASTOMOSIS Colon cancer
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副词重叠与重叠式副词 被引量:6
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作者 李媚乐 《辽宁大学学报(哲学社会科学版)》 北大核心 2005年第2期66-68,共3页
本文简要总结了副词重叠与重叠式副词的研究历程与现状,通过对《现代汉语语法信息词典详解》(第二版)副词库的考察,力求客观地对副词重叠前后语义语用变化、修辞效果的差异等进行综合分析,并就副词重叠研究的取向、范围和方式以及副词... 本文简要总结了副词重叠与重叠式副词的研究历程与现状,通过对《现代汉语语法信息词典详解》(第二版)副词库的考察,力求客观地对副词重叠前后语义语用变化、修辞效果的差异等进行综合分析,并就副词重叠研究的取向、范围和方式以及副词重叠动因等问题提出一些拙见,与学界共同探讨。 展开更多
关键词 副词 重叠 重叠式 基式 重叠动因
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摇摆运动引起的波动与自然循环密度波型脉动的叠加 被引量:14
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作者 谭思超 庞凤阁 《核动力工程》 EI CAS CSCD 北大核心 2005年第2期140-143,共4页
针对海洋条件(即摇摆工况)下,核动力装置自然循环流动不稳定的特点进行了实验研究。结果表明,摇摆引起的流量波动的附加量与自然循环密度波型脉动的流量脉动相叠加,加剧了系统的不稳定,通过频谱分析,分析了叠加效应的强弱。
关键词 自然循环 摇摆 流动不稳定 叠加
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THE PHASE-OFFSET OVERLAPPED WAVE TECHNIQUE 被引量:3
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作者 Liang Dequn (Dalian Maritime University, Dalian 116026)Liang Weihua (Dalian University of Science and Technology, Dalian 116026)Sun Changnian (Telecom Sino Group, Sunnyvale, California, USA, 94086) 《Journal of Electronics(China)》 2003年第2期121-127,共7页
A new digital communication technology based on the Phase-Offset Overlapped Waves (POOW) has been introduced in this letter. The waves can be considered as a special multicarrier different from traditional ones. The s... A new digital communication technology based on the Phase-Offset Overlapped Waves (POOW) has been introduced in this letter. The waves can be considered as a special multicarrier different from traditional ones. The sub-waves in a coded word's period of the POOW are sine waves and have the same frequencies, but different starting phases. The most important characteristic is that these sub-waves are the piecewise functions and not orthogonal in a code word period. The decoding can be implemented by solving a linear equation group. This code has very high efficiency and thus the data transmission rate is increased greatly. 展开更多
关键词 Digital communications CODING MULTICARRIER Phase-offset overlapped wave
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基于RBFNN和GA的重叠峰分辨新技术 被引量:8
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作者 李一波 黄小原 《应用科学学报》 CAS CSCD 2002年第1期99-103,共5页
根据光谱线型函数和色谱峰型函数的 (近似 )径向对称性和紧支性 ,首先构造了以线型或峰型函数为基函数的径向基函数神经网络 ( RBFNN) ,在 RBFNN学习算法中引入了基于可行域约束和共享小生境技术的遗传算法( GA) ,从而使 RBFNN具有了结... 根据光谱线型函数和色谱峰型函数的 (近似 )径向对称性和紧支性 ,首先构造了以线型或峰型函数为基函数的径向基函数神经网络 ( RBFNN) ,在 RBFNN学习算法中引入了基于可行域约束和共享小生境技术的遗传算法( GA) ,从而使 RBFNN具有了结构自学习和参数优化的能力 .最后将具有结构自学习能力的 RBFNN成功地引入至谱图的重叠峰解析辨识研究中 ,试图建立一种适应光谱和色谱谱图重叠峰解析辨识的统一架构 ,并达到了预期的目的 .为了提高解析辨识的成功率 ,避免遗传算法的盲目搜索 ,文章还将参数的约束关系作为罚函数引入至遗传算法的适应值函数中 ,极大地限制了解的空间 ,减少了病态解发生的概率 . 展开更多
关键词 RBFNN GA 重叠峰 径向基函数神经网络 遗传算法 光谱 色谱 解析辨识
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Node correlation clustering algorithm for wireless multimedia sensor networks based on overlapped FoVs 被引量:8
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作者 ZHANG Qian-yan WANG Ru-chuan +1 位作者 SHA Chao HUANG Hai-ping 《The Journal of China Universities of Posts and Telecommunications》 EI CSCD 2013年第5期37-44,共8页
In this paper, a clustering algorithm is proposed based on the high correlation among the overlapped field of views for the wireless multimedia sensor networks. Firstly, by calculating the area of the overlapped field... In this paper, a clustering algorithm is proposed based on the high correlation among the overlapped field of views for the wireless multimedia sensor networks. Firstly, by calculating the area of the overlapped field of views (FoVs) based on the gird method, node correlations have been obtained. Then, the algorithm utilizes the node correlations to partition the network region in which there are high correlation multimedia sensor nodes. Meanwhile, in order to minimize the energy consumption for transmitting images, the strategy of the cluster heads election is proposed based on the cost estimation, which consists of signal strength and residual energy as well as the node correlation. Simulation results show that the proposed algorithm can balance the energy consumption and extend the network lifetime effectively. 展开更多
关键词 wireless multimedia sensor networks overlapped FoVs node correlation CLUSTERING
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Development process of muzzle flows including a gun-launched missile 被引量:8
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作者 Zhuo Changfei Feng Feng Wu Xiaosong 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2015年第2期385-386,共2页
Numerical investigations on the launch process of a gun-launched missile from the muz- zle of a cannon to the free-flight stage have been performed in this paper. The dynamic overlapped grids approach are applied to d... Numerical investigations on the launch process of a gun-launched missile from the muz- zle of a cannon to the free-flight stage have been performed in this paper. The dynamic overlapped grids approach are applied to dealing with the problems of a moving gun-launched missile. The high-resolution upwind scheme (AUSMPW +) and the detailed reaction kinetics model are adopted to solve the chemical non-equilibrium Euler equations for dynamic grids. The development process and flow field structure of muzzle flows including a gun-launched missile are discussed in detail. This present numerical study confirms that complicated transient phenomena exist in the shortly launching stages when the gun-launched missile moves from the muzzle of a cannon to the free- flight stage. The propellant gas flows, the initial environmental ambient air flows and the moving missile mutually couple and interact. A complete structure of flow field is formed at the launching stages, including the blast wave, base shock, reflected shock, incident shock, shear layer, primary vortex ring and triple point. 展开更多
关键词 Blast flow field Chemical reaction Computational fluiddynamics Dynamic overlapped grids Gun-launched missile Muzzle flows
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On-orbit Geometric Calibration of Linear Push-broom Optical Satellite Based on Sparse GCPs 被引量:10
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作者 Yingdong PI Baorong XIE +3 位作者 Bo YANG Yiling ZHANG Xin LI Mi WANG 《Journal of Geodesy and Geoinformation Science》 2020年第1期64-75,共12页
The paper presents a geometric calibration method based on the sparse ground control points (GCPs), aiming to the linear push-broom optical satellite. This method can achieve the optimal estimate of internal and exter... The paper presents a geometric calibration method based on the sparse ground control points (GCPs), aiming to the linear push-broom optical satellite. This method can achieve the optimal estimate of internal and external parameters with two overlapped image pair along the charge-coupled device (CCD), and sparse GCPs in the image region, further get rid of the dependence on the expensive calibration site data. With the calibrated parameters, the line of sight (LOS) of all CCD detectors can be recovered. This paper firstly establishes the rigorous imaging model of linear push-broom optical satellite based on its imaging mechanism. And then the calibration model is constructed by improving the internal sensor model with a viewing-angle model after an analysis on systematic errors existing in the imaging model is performed. A step-wise solution is applied aiming to the optimal estimate of external and internal parameters. At last, we conduct a set of experiments on the ZY-3 NAD camera and verify the accuracy and effectiveness of the presented method by comparison. 展开更多
关键词 OPTICAL SATELLITE on-orbit geometric calibration overlapped image pair SPARSE GCPs viewing-angle
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多线程技术及其在串口通信中的应用 被引量:6
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作者 贾广雷 刘培玉 耿长欣 《计算机科学》 CSCD 北大核心 2002年第8期148-149,130,共3页
1引言 多线程技术能很好地解决并发多任务问题,提高资源的利用率,因此在计算机的许多研究领域都对其进行了探讨,从不同的角度实现了多线程.从大的方面讲,一是从计算机体系结构、多线程处理机硬件实现对多线程,即多线程计算机的研究.如St... 1引言 多线程技术能很好地解决并发多任务问题,提高资源的利用率,因此在计算机的许多研究领域都对其进行了探讨,从不同的角度实现了多线程.从大的方面讲,一是从计算机体系结构、多线程处理机硬件实现对多线程,即多线程计算机的研究.如Stanford的DASH、MIT的Alewife等;一是从软件角度实现多线程,即也可以在非多线程处理机上实现,这一方面主要表现在多线程编译系统、多线程操作系统成为系统软件的主流,如IBM的OS/2、Sun的Solaris、Mircosoft的win-dows系列等. 展开更多
关键词 串口通信 多线程技术 进程 程序设计 操作系统
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Spline wavelet overlapped peaks analysis 被引量:3
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作者 Xiaoyong Zou Jinyuan Mo 《Chinese Science Bulletin》 SCIE EI CAS 1999年第10期901-904,共4页
The proposed method of spline wavelet overlapped peaks analysis is based on the model of wavelet multifrequency channel decomposition. If the suitable optimal wavelet basis and frequency scale value are selected, the ... The proposed method of spline wavelet overlapped peaks analysis is based on the model of wavelet multifrequency channel decomposition. If the suitable optimal wavelet basis and frequency scale value are selected, the useful information can be extracted from noised overlapped signal. Then, according to the linear relationship between individual components in blurred version, multiple linear regression in low frequency domain is employed to resolve highly overlapped peaks. The results show that even signal-to-noise (S/N) decreases to 0.2, relative errors of peak intensity are less than 12% and the sum of square deviations Q is less than 0. 展开更多
关键词 WAVELET FILTERING overlapped PEAKS resolution.
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A graphene rheostat for highly durable and stretchable strain sensor 被引量:7
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作者 Jing Ren Wenjun Zhang +4 位作者 Yubo Wang Yaxiong Wang Jun Zhou Liming Dai Ming Xu 《InfoMat》 SCIE CAS 2019年第3期396-406,共11页
Strain sensors for human health monitoring are of paramount importance in wearable medical diagnostics and personal health monitoring.Despite extensive studies,strain sensors with both high durability and stretchabili... Strain sensors for human health monitoring are of paramount importance in wearable medical diagnostics and personal health monitoring.Despite extensive studies,strain sensors with both high durability and stretchability are still desired,particularly with the stability for different environmental conditions.Here,we report a series of strain sensors possessing the graphene network with a high density of intermittent physical interconnections,which produces the relative resistance change by varying the overlap area between the neighboring graphene sheets under stretching and releasing,analogous to the slide rheostat working in electronics.Our in-situ transmission electron microscope observation reveals the full recoverability of the structure from large deformation upon unloading for ensuring the exceptional cycle stability of our material on monitoring full-range body movements.The stable response is also demonstrated over wide temperature range and frequency range,because the peculiar dynamic structure can be maintained through the self-adjustment to the thermal expansion of the bulk material.Based on the working mechanism of graphene“slide rheostat,”the sensing properties of the strain sensor are tailored by tuning the graphene network structure with different mass densities using different concentrations of graphene oxide dispersion,while the stretchability and sensitivity can be separately optimized for different application requirements. 展开更多
关键词 GRAPHENE human body movements monitoring overlapped graphene sheets strain sensor threedimensional graphene network
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Assessing the deformation response of double-track overlapped tunnels using numerical simulation and field monitoring 被引量:6
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作者 Yao Hu Huayang Lei +4 位作者 Gang Zheng Liang Shi Tianqi Zhang Zhichao Shen Rui Jia 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2022年第2期436-447,共12页
The unprecedented rate of metro construction has led to a highly complex network of metro lines.Tunnels are being overlapped to an ever-increasing degree.This paper investigates the deformation response of double-trac... The unprecedented rate of metro construction has led to a highly complex network of metro lines.Tunnels are being overlapped to an ever-increasing degree.This paper investigates the deformation response of double-track overlapped tunnels in Tianjin,China using finite element analysis(FEA)and field monitoring,considering the attributes of different tunneling forms.With respect to the upper tunneling,the results of the FEA and field monitoring showed that the maximum vertical displacements of the ground surface during the tail passage were 2.06 mm,2.25 mm and 2.39 mm obtained by the FEA,field monitoring and Peck calculation,respectively;the heaves on the vertical displacement curve were observed at 8 m(1.25D,where D is the diameter of the tunnel)away from the center of the tunnel and the curve at both sides was asymmetrical.Furthermore,the crown and bottom produce approximately0.38 mm and 1.26 mm of contraction,respectively.The results of the FEA of the upper and lower sections demonstrated that the tunneling form has an obvious influence on the deformation response of the double-track overlapped tunnel.Compared with the upper tunneling,the lower tunneling exerted significantly less influence on the deformation response,which manifested as a smaller displacement of the strata and deformation of the existing tunnel.The results of this study on overlapped tunnels can provide a reference for similar projects in the future. 展开更多
关键词 Double-track overlapped tunnels Deformation response Finite element analysis(FEA) Field monitoring Upper and lower tunneling
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Resource-constrained Project Scheduling with Overlapping Activities Based on Extended Dependency Structure Matrix 被引量:4
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作者 BAI Li-biao SONG Hong-yan +1 位作者 BAI Si-jun GUO Yun-tao 《International Journal of Plant Engineering and Management》 2013年第4期204-211,共8页
Dependency Structure Matrix (DSM) is a successful and powerful tool for representing and analyzing dependencies between the items, but for external influencing factors it cannot charge effectively. This paper sets t... Dependency Structure Matrix (DSM) is a successful and powerful tool for representing and analyzing dependencies between the items, but for external influencing factors it cannot charge effectively. This paper sets the stage for connecting the activities and resources, which not only considers information flow but also resources constrains.We first introduce the DSM to represent the degree of overlapping between the activities in a project. Then we present the Extended DSM combined former DSM and resource factors to calculate the project duration. Finally, the practical significance of the Extended DSM is confirmed by an illustrative example. 展开更多
关键词 overlapped Extended DSM resource constraint project duration
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在远程数据采集中多线程串口通信的应用 被引量:1
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作者 江冰 奚吉 《微处理机》 2003年第1期59-61,共3页
主要阐述了利用多线程技术和重叠操作模式进行串口通信的一种编程方式 。
关键词 远程数据采集 多线程串口通信 数据处理 I/O操作 用户界面线程
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基于改进的独立分量分析混叠通信信号盲分离
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作者 韩树楠 陈铸龙 卢勇君 《现代防御技术》 北大核心 2024年第3期87-95,共9页
针对时域与频域均交叠的多路数字带通通信信号盲分离问题,利用布谷鸟搜索算法,研究了一种新的基于独立成分分析的盲分离方法。在均匀线阵下,构建混叠信号模型;从最大化信号非高斯性角度,将盲源分离问题转化为信号峭度的优化问题;利用布... 针对时域与频域均交叠的多路数字带通通信信号盲分离问题,利用布谷鸟搜索算法,研究了一种新的基于独立成分分析的盲分离方法。在均匀线阵下,构建混叠信号模型;从最大化信号非高斯性角度,将盲源分离问题转化为信号峭度的优化问题;利用布谷鸟搜索算法优化求解近似峭度的代价函数,将迭代产生的适应度值最高的个体作为解混向量,实现源信号的分离。与已有的基于固定点算法的独立成分分析方法相比,该方法能够克服其无法分离时频域混叠的振幅键控(ASK)信号的限制,适用于任何调制类型的数字带通通信信号盲分离。通过仿真实验验证了方法的有效性并分析了方法性能,实验结果表明在较低信噪比条件下,分离的信号具有较高信干比,说明方法具有较高的鲁棒性。 展开更多
关键词 独立成分分析 布谷鸟搜索 通信信号 时频域 混叠 盲分离
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异步串行通讯在实时监控系统中的应用 被引量:3
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作者 王晓柱 姜合 任一男 《仪表技术与传感器》 CSCD 北大核心 2004年第6期23-25,共3页
针对"请求/应答"通讯模式探讨了采用异步(overlapped)串行通讯方式实现实时通讯的关键技术;给出了具有容错自恢复功能的通讯程序设计方法;提出了解决串口临界资源竞争和同步问题的监控命令抢先调度机制;结合实际工程应用给出... 针对"请求/应答"通讯模式探讨了采用异步(overlapped)串行通讯方式实现实时通讯的关键技术;给出了具有容错自恢复功能的通讯程序设计方法;提出了解决串口临界资源竞争和同步问题的监控命令抢先调度机制;结合实际工程应用给出了部分相关VB程序设计代码。 展开更多
关键词 串行通讯 异步 容错 抢先 调度
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On Channel Assignment for Multicast in Multi-Radio Multi-Channel Wireless Mesh Networks:A Survey 被引量:6
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作者 WANG Jihong SHI Wenxiao JIN Feng 《China Communications》 SCIE CSCD 2015年第1期122-135,共14页
The major challenge faced by wireless mesh networks is the capacity reduction caused by interference,and interference can be reduced or even eliminated through appropriate channel assignment.This article presents a co... The major challenge faced by wireless mesh networks is the capacity reduction caused by interference,and interference can be reduced or even eliminated through appropriate channel assignment.This article presents a comprehensive survey of channel assignment schemes for multicast in multi-radio multi-channel wireless mesh networks.We analyze the state-of-the-art channel assignment schemes for multicast and provide comprehensive taxonomy of the latest work.In general,we classify the channel assignment schemes for multicast into two types,that is,sequential multicast routing and channel assignment(SMRCA)and joint multicast routing and channel assignment(JMRCA).Detailed review of channel assignment schemes in each category is provided.Possible future research directions and corresponding solutions are also explored to motivate research interests in the field of channel assignment for multicast in wireless mesh networks. 展开更多
关键词 MULTICAST channel assignment INTERFERENCE partially overlapped channels
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Performance of overlapped shield tunneling through an integrated physical model tests,numerical simulations and real-time field monitoring 被引量:5
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作者 Junlong Yang Chen Liu +1 位作者 Qiushi Chen Xiongyao Xie 《Underground Space》 SCIE EI 2017年第1期45-59,共15页
In this work,deformations and internal forces of an existing tunnel subjected to a closely overlapped shield tunneling are monitored and analyzed using a series of physical model experiments and numerical simulations.... In this work,deformations and internal forces of an existing tunnel subjected to a closely overlapped shield tunneling are monitored and analyzed using a series of physical model experiments and numerical simulations.Effects of different excavation sequences and speeds are explicitly considered in the analysis.The results of the physical model experiments show that the bottom-up tunneling procedure is better than the top-down tunneling procedure.The incurred deformations and internal forces of the existing tunnel increase with the excavation speed and the range of influence areas also increase accordingly.For construction process control,real-time monitoring of the power tunnel is used.The monitoring processes feature full automation,adjustable frequency,real-time monitor and dynamic feedback,which are used to guide the construction to achieve micro-disturbance control.In accordance with the situation of crossing construction,a numerical study on the performance of power tunnel is carried out.Construction control measures are given for the undercrossing construction,which helps to accomplish the desired result and meet protection requirements of the existing tunnel structure.Finally,monitoring data and numerical results are compared,and the displacement and joint fracture change models in the power tunnel subject to the overlapped shield tunnel construction are analyzed. 展开更多
关键词 overlapped tunnel Automatic monitoring Micro-disturbance control
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新型搭接螺旋折流板换热器性能研究 被引量:5
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作者 曹兴 杜文静 程林 《工程热物理学报》 EI CAS CSCD 北大核心 2013年第6期1130-1132,共3页
本文提出了一种新型搭接螺旋折流板换热器。数值模拟结果表明,相邻折流板轴向周边重叠的结构有效地减轻了三角区漏流,使轴向速度沿径向的分布更加均匀;与1/4扇形螺旋折流板换热器相比,其壳程传热系数更高,压降更低,综合性能在小螺旋角... 本文提出了一种新型搭接螺旋折流板换热器。数值模拟结果表明,相邻折流板轴向周边重叠的结构有效地减轻了三角区漏流,使轴向速度沿径向的分布更加均匀;与1/4扇形螺旋折流板换热器相比,其壳程传热系数更高,压降更低,综合性能在小螺旋角下更具优势。 展开更多
关键词 换热器 螺旋折流板 搭接 新型 数值模拟
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